[ImperialCrown]

Welcome to Allpar. Do you have gauges and dash indicator lights?
Automatic or Manual? The starter relay may be missing it's ground at the clutch pedal or the Neutral/Reverse safety switch?

 

[ImperialCrown]

I would Google around for a wiring diagram so you can trace wire colors. Autozone may have free diagrams on their website. See where the power stops.

 

[ImperialCrown]

Have a close look at the main bulkhead (firewall) connector terminals. It helps if you unplug them completely and inspect for terminal seating, burnt or melted plastic. They feed and return from the ignition switch. It sounds a circuit branch is out.

 

[ImperialCrown]

A jump start will get everything working? Maybe a problem with the battery terminals or cables? Are you jumping right to the battery terminals?
Is there a ground strap or cable missing between the frame or body or engine? All 3 need to be common to battery (-) with each other.
Does this truck have a single battery or dual batteries?